ITMI20011824A1 - PROCEDURE FOR ERROR DIAGNOSIS IN A CLUTCH ACTUATOR - Google Patents

Description

DESCRIPTION

The invention relates to a method for diagnosing an error in a clutch actuator according to the preamble of the patent claims 1, 10, 12 and 15.

In connection with the concept of safety monitoring for automatic gearboxes, it has emerged that many critical situations are mainly caused by the actuation of the clutch, for example when it opens and closes unwantedly. Knowledge of the momentary state of the clutch from time to time is therefore of utmost importance.

In connection with automatic / automated clutches or gearboxes it is known to derive a measured quantity, which indicates the position of the clutch actuator. However, since a sensor for detecting the position of the clutch actuator can fundamentally also fail, like any other technical component, the position, indicated by the sensor, of the clutch actuator is not unlimitedly reliable. A monitoring of the clutch position or the position of the clutch actuator is therefore highly recommended in connection with safety monitoring in automatic gearboxes.

In this regard, it is known to implement a monitoring device for the sensor determining the position of the clutch actuator in the form of a plausibility on the basis of minimum and maximum values. However, only a few extreme sensor errors, such as a short circuit or a cable break, can be detected with this.

The object of the present invention therefore consists in providing a method for diagnosing an error in a clutch actuator, which makes it possible to relatively reliably monitor the position of the clutch actuator as well as the state of the clutch.

This task is solved by a method for diagnosing an error in a clutch actuator with the features of patent claim 1. Furthermore, this is solved by a method for diagnosing an error in a clutch actuator with the features of patent claim 10. Furthermore this is solved by a method for diagnosing an error in a clutch actuator with the features of patent claim 12.

The aim of the invention is also solved by means of a device according to claim 15.

The substantial advantage of the present invention is that a very broad recognition of errors in the clutch actuator is achieved in a relatively simple way and by correlating the position, measured by a sensor, of the clutch actuator with a position of the clutch actuator. actuator, which is estimated by an actuator model as a function of the respective control variable.

Advantageous embodiments of the invention result from the dependent claims.

The invention and its embodiments in connection with the figures are illustrated in more detail below.

Figure 1 shows a block diagram of a first embodiment of the invention for monitoring the clutch actuator;

Figure 2 shows a block diagram of a second embodiment of the invention for monitoring the clutch and clutch actuator;

Figure 3 shows a block diagram of a third embodiment of the invention for monitoring the clutch; And

Figure 4 shows an improvement of the invention.

In Figure 1, 1 indicates a clutch actuator. Reference mark 2 indicates a model unit of the actuator, in which the actuator positions provided for each time are calculated for all the possible setting variables for the clutch actuator 1. By means of the automatic gearbox (ASG), actuator variables are applied to both clutch actuator 1 and model unit of actuator 2 for actuation of the clutch. Depending on a newly applied actuating variable, for an output 11 of the clutch actuator 1 generates an electrical signal from a sensor, corresponding to the actuator position caused on the basis of the control variable (signal for the measured actuator position).

Corresponding to the control variable present at the same time in the model unit of actuator 2, an expected actuator position (estimated actuator position) is calculated via the model unit of actuator 2 and is prepared at output 21 of the actuator. model unit of actuator 2 as a signal for the estimated actuator position. The electrical signals, obtained at outputs 11 and 21, for the measured actuator position and for the estimated actuator position are compared with each other in a comparison unit 3, for example a sum point, and the signal presents at the output 31 of the comparison unit 3 is fed to a computing unit 4, which at its output 41 generates a corresponding status signal (status). In the case of an approximate coincidence of the signals for the measured actuator position and the estimated actuator position, the computing unit 4 on the basis of an evaluation algorithm concludes on a functioning clutch actuator and at the same time on a functioning sensor for determining the position of the clutch actuator. If there are large differences between the signals for the measured actuator position and the estimated actuator position it is instead concluded that there is an error in the clutch actuator 1 or in the sensor for determining the position of the actuator. clutch 1.

In order to avoid an increasing distancing of the positions, which can be caused for example by normal frictional effects, it is recommended to trace and evaluate the output signal of the comparison unit 3 via a return conductor 24 to the input 22 of the control unit. actuator model.

In the following, an embodiment is illustrated in relation to Figure 2, in the case of which not only an indication is given on the function of the clutch actuator and / or the sensor for the position of the clutch actuator, but also takes into account of the effects of an adjustment of the clutch actuator 1, i.e. the application or variation of a clutch moment. Details of Figure 2, which have already been illustrated in relation to Figure 1, are indicated in the corresponding manner.

The signal for the measured position of the actuator, present at the output 11 of the clutch actuator 1, is also applied to the input 50 of a unit 5 for the behavior of the clutch and the dynamics of the engine, which at its output 51 applies an electrical signal determined by a sensor and corresponding to the actual number of revolutions of the engine. This signal for the actual engine speed is applied to input 60 of a further comparison device 6.

Correspondingly, the signal obtained at the output 21, which corresponds to the estimated actuator position, is applied to the input 70 of a unit 7, which on the basis of the respective estimated positions of the actuator calculates the expected engine revolutions and at its output 71 provides corresponding electrical signals for the estimated engine rpm. The signal for the actual engine speed and the estimated engine speed are applied from the output 71 to the input 62 of the comparison device 6, for example a sum point, and compared with each other. At output 61 there is therefore a signal {Res 2), which is evaluated by an unrepresented calculation unit and on the basis of its size, which corresponds to the difference between the signals for the number of actual engine revolutions and for the number of estimated engine revolutions, makes it possible to conclude on the state of the clutch. The output signal Res 1, present at the output 31 of the comparison device 3, is evaluated by the computing unit 4 already illustrated in relation to Figure 1, and also makes it possible to provide an enunciation on the state of the actuator.

The embodiment of Figure 2 thus allows for additional error recognition possibilities. For example, when a sensor error for the position of the clutch actuator 1 occurs during a starting or shifting process, a large output signal Res 1 will result very quickly at output 31 of the comparison unit 3, while the output signal Res 2 at the output 61 of the comparison unit 6 remains small, since the clutch actuator 1 actually performs the intended displacement of the clutch. On the other hand, when the clutch actuator 1 is per se faulty, then both the output signal Res 1 at output 31 and the output signal Res 2 at output 61 will grow rapidly. An error of the clutch respectively of its release system can also be determined when the output signal Res 1 at the output 31 of the comparison unit 3 remains small, while the output signal Res 2 at the output 61 of the control unit comparison 6 takes on great values.

Thanks to the error localization illustrated, there are therefore considerable advantages as regards the safety or availability of a vehicle with automated gearbox. In order to avoid possible displacement of the signals for the actual engine speed and for the estimated engine speed, the output signal Res 2 can be returned via a return conductor 64 to the unit 7 and evaluated.

Figure 3 shows a simplified embodiment, in which monitoring of the clutch actuator is dispensed with. Details of Figure 3, which have already been illustrated in connection with Figure 2, are indicated in the corresponding manner. In the case of the embodiment of Figure 3, the model unit of the actuator 2 as well as the comparison unit 3 are missing. Consequently, the signal, determined by the sensor for the position of the clutch actuator, for the measured actuator position is applied to the input 50 of the motor control unit 5. At the same time, the signal for the measured actuator position is applied to input 70 of unit 7. The signal for the actual motor speed, which has output 51 of unit 5, is compared by the comparison unit 6 with the signal for the engine speed estimated from the output 71 of the unit 7, so that as a function of the magnitude of the output signal Res 2 at the output Gl of the comparison unit 6 conclusions can be drawn about the state of the clutch . Consequently, errors in the clutch or the release system can be detected.

In the following, in connection with Figure 4, an error diagnosis procedure is illustrated, according to which an error in the disengagement system of a clutch or of the clutch itself can be recognized, since a moment is continuously transmitted by the clutch. This means that no gear can be engaged even if the engine is running at a standstill. If the insertion is performed too often, then a corruption of the synchronization can occur.

In figure 4 the clutch which transmits the torque of the engine 100 to the gearbox 200 is indicated with 300. The rotation of the gearbox 200 is transmitted to the wheels 500.

In order to be able to recognize a situation in which a twisting moment is erroneously continuously transmitted from the engine 100 to the gearbox 200 via the clutch 300, an electrical signal is determined by means of a sensor SI which indicates the state of rest of the vehicle, by means of the sensor S3 a electric signal which indicates whether the motor 100 is in operation or rotates, and by means of a sensor S2 an electric signal is generated which indicates whether a forward gear engaged by the automatic gearbox 200 cannot be synchronized within a predetermined time. The three electrical signals mentioned of the sensors S1, S2 and S3 are passed to a logic unit Und 400, which then, when the three signals are present, generate an error flag F which indicates that the error described is present in the control system. disengagement. When the error flag F is generated, the gearbox 200 engages the gear in neutral.

The error flag F is preferably cleared when a driver communicates his will to engage first gear by operating the gearshift lever 200 before a predetermined time has elapsed.

Advantageously, thanks to the method illustrated in connection with Figure 4, the following errors can be recognized or disadvantages can be avoided.

1. An undesired drag moment on the clutch 200 in the quiescent state of the vehicle can be recognized and / or avoided.

2. A faulty hydraulic system or incorrect operation of the vehicle can be recognized.

3. A defective shift actuator can be determined.

4. After a fault, which is not recognized by a plausibility of the wheel speed, of the wheel speed to zero, the incorrect engagement of the first gear can be recognized.

The patent claims filed with the application are proposed for formulation without prejudice to obtaining a broader patent protection. The Applicant reserves the right to claim still further combinations of characteristics disclosed so far only in the description and / or in the drawings.

The references used in the sub-claims refer to the further execution of the object of the main claim by means of the characteristics of the respective sub-claim, they are not to be understood as the renunciation of obtaining an autonomous objective protection for the combinations of characteristics of the sub-claims containing the references .

Since the objects of the sub-claims as regards the state of the art on the priority day can form their own and autonomous inventions, the applicant reserves the right to make them the subject of independent claims or divisional applications. They may also contain autonomous inventions, which have a configuration independent of the objects of the preceding sub-claims.

The embodiments are not to be understood as a limitation of the invention. On the other hand, numerous variations and modifications are possible within the scope of the present description, in particular such variations, elements and combinations and / or materials, which for example by combining or modifying individual characteristics or elements or process steps, described in the general description and in the embodiments as well as in the claims and contained in the drawings, are detectable by the skilled person as regards the solution of the task, and by means of combinable characteristics lead to a new object or to new process steps or sequences of the process steps, also with regard to methods manufacturing, testing and work.

Claims (15)

CLAIMS 1. Procedure for diagnosing an error in a clutch actuator, where on the basis of a control variable present at an input of the clutch actuator, which is generated by a control unit in particular of an automatic gearbox , of an automated clutch or CVT gearbox, a signal for the measured actuator position is generated at the output of the clutch actuator, characterized in that the control variable is also applied to an input of a model unit of the actuator, and from this a signal for the predicted actuator position is calculated and prepared at an output, by the fact that the signal for the measured actuator position and the signal for the estimated actuator position are compared between them in a comparison unit, where the output signal of the comparison unit is fed to a calculation unit, which generates a character status signal at its output for the functionality of the clutch actuator. Method according to claim 1, characterized in that in the case of an approximate coincidence of the signal for the measured actuator position and the signal for the estimated actuator position, the computing unit generates a status signal indicating the functionality of the clutch actuator and the functionality of the sensor for determining the position of the clutch actuator. Method according to claim 1, characterized in that if a maximum permissible deviation between the signal for the measured actuator position and the signal for the estimated actuator position is exceeded, a status signal, which indicates an error in the clutch actuator and / or the sensor for determining the position of the clutch actuator. Method according to one of claims 1 to 3, characterized in that the output signal of the comparison unit can be returned via a return line to the model unit of the actuator, in order to avoid an undesired reciprocal separation of the signal for the measured actuator position and the signal for the estimated actuator position. Method according to one of claims 1 to 4, characterized in that the signal for the measured actuator position is also fed to the input of a unit for clutch behavior and engine dynamics, which it applies to its output an electrical signal determined by a sensor, which corresponds to the actual number of revolutions of the engine, by the fact that the signal for the position of the estimated actuator is applied to the input of a unit, which at its output as a signal for the number of revolutions engine speed generates a calculated signal based on the signal for the estimated actuator position and the expected engine moment, and on the fact that the signal for the actual engine speed and the signal for the estimated engine speed they are fed to a comparison unit, which generates a further output signal at an output, which is evaluated by a further calculation unit. 6. Method according to claim 5, characterized in that the further calculation imit generates a status signal indicating the functionality of the clutch actuator, when the output signal at the output of the comparison device has an approximate coincidence between the signal for the actual engine speed and the signal for the estimated engine speed. Method according to claim 6, characterized in that in the case of further presence of a status signal on the computing unit, which indicates a predetermined difference between the signal for the measured actuator position and the signal for the position of the The estimated actuator, during a shift starting process it is concluded that there is a sensor error for the position of the clutch actuator. Method according to claim 5 or 6, characterized in that when the output signal of the comparison unit shows a predetermined difference between the signal for the measured actuator position and the signal for the estimated actuator position and the comparison device generates a further output signal, which indicates a predetermined difference between the signal for the actual engine speed and the signal for the estimated engine speed, it is concluded that there is an actuator error of the clutch. Method according to claim 5 or 6, characterized in that when the comparison unit indicates an approximate coincidence between the signal for the measured actuator position and the signal for the estimated actuator position and the comparison device indicates a predetermined difference between the signal for the actual engine rpm and the signal for the estimated engine rpm, it is concluded that there is an error of the clutch respectively of its release system or of the rpm sensor of the motor. 10. Procedure for an error diagnosis in a clutch actuator, where on the basis of an adjustment variable present at an input of the clutch actuator, which is generated by a control unit, at the output of the clutch actuator a signal is generated for the measured actuator position, characterized in that the signal for the measured actuator position is applied to an input of a unit for clutch behavior and engine dynamics, which generates on m 'output a signal corresponding to the actual number of revolutions of the engine, and is applied to a m a m ity input, which at its output generates m electrical signal for the estimated number of revolutions of the engine, since the signal for the number of revolutions of the engine and the signal for the estimated engine speed are compared with each other in terms of comparison, so that in fm tion of the magnitude of the output signal at the output of the device a comparison can be drawn about the state of the clutch. Method according to m a of claims 5 to 10, characterized in that the output signal of the comparison device is fed through m further conductor returning to m ity, in order to avoid undesired reciprocal separation of the signal due to the number of revolutions. of the actual engine and the signal for the estimated engine rpm. 12. Method for diagnosing an error in friction, characterized in that a first electrical signal is generated by means of a first sensor indicating a state of rest of a vehicle, by the fact that a second electrical signal is generated by means of a second sensor, which indicates if a forward gear engaged by the automatic gearbox cannot be synchronized within a predetermined time, by the fact that a third sensor is generated a third electrical signal, which indicates whether the engine is running or not, and by the fact that the first signal electrical, the second electrical signal and the third electrical signal are given to a logic member Und which, when the three signals are present, generates an error flag indicating an error in the release system. 13. Method according to claim 12, characterized in that when the error flag is generated, the gearbox engages the gear in neutral. Method according to claim 12 or 13, characterized in that the error flag is cleared when the gear selector lever is operated in first gear before a predetermined time has elapsed due to the vehicle error. 15. Device for the automated actuation of a clutch with a clutch actuator, in particular for carrying out the method according to one of the preceding claims.